Telephone system.



F. R. PARKER & E. R. CORWIN.

TELEPHONE SYSTEM.

APPLICATION FILED DEQ.7, 1904. RENEWED JULY 13, 1910.

1,095,666. Patented May 5, 1914 mvsNToRs:

COLUMBIA PLANOGRAPH coLwAsl-xmclToN, D e.

UNITED STATES PATENT ()FFTQE.

FREDERICK R. PARKER AND ELMER R. CORWIN, OF CHICAGO, ILLINOIS; SAID CORWIN ASSIG'NOR TO SAID PARKER.

TELEPHONE SYSTEM.

Patented May 5, 1914.

Application filed December 7', 1904, Serial No. 235,877. Renewed July 13, 1910. Serial No. 571,846.

To all whom it may concern:

Be it known that we, FREDERICK R. PAR- KER and ELMER R. CoRwIN, citizens of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Telephone Systems, of which the following is a specification, reference being had to the accompanying drawing, illustrating same.

Our invention relates to a telephone system, our objects being, first, to provide improved means for operating and controlling the supervisory signals in; such a system, and second, to provide a dead ring on one of the spring jacks of a telephone line, so as to avoid closing the circuit of the central source of electricity at this ring during the operation of making connection with the telephone line.

Supervisory signals are usually provided in plug-cord connecting circuits for telephone lines, one for'each connecting cord. These signals are for the purpose of enabling the operator to tell whether the subscriber has his telephone receiver off of the switch-hook, for use, or whether he has finished conversation and has again placed the receiver on the switch-hook, when connection is made with his line. They enable the operator to tell the condition of the subscribers lines when connection is made therewith. As eachconnecting cord is supplied with such a signaling device, each subscribers line has an individual supervisory signal therefor when connection is made therewith.

It is the usual practice to employ relays in the plug-cord circuit for the purpose of closing respective circuits through the supervisory signaling devices, preferably signal lamps, but in this present invention we preferably employ a third conductor in the connecting cord and plug, adapted to cooperate with a third contact of a spring ack of the line and thereby close the circuit of the supervisory signal at this point when connection is made with the line. Then we employ a relay preferably included in the talking circuit of the telephone line, for controlling this supervisory signal circuit while connection is made with the line. Any suitable source of electricity may be used for supplying current for the supervisory signal.

e will now more particularly describe our invention by reference to the accompanying drawing illustrating certain embodiments thereof, in which are shown two subscribers lines and central station signaling and connecting apparatus therefor. The line of subscriber A extends in two limbs b and 0 to the central station. Limb Z) is connected through winding (Z of relay N, to contacts it h of the spring'jacks O and P. Limb c is connected through winding 6 of relay N, to contacts j j of the spring jacks O and P. Springs 91 and 1* of relay N are connected to limbs 12 and 0, respectively, of the telephone line. Armature z, of relay N, is adapted to disengage spring 11- from contacts 0 and p, and spring r from contact 9, when in an operated or attracted condition. Contact 0 is connected through conductor m, to pole m of battery K; contact 9 is connected through conductor 8, and signal lamp 2?, to pole p of battery L; and contact 7) is connected through conductor Z, tojack contacts 11 i of spring jacks O and P. Batteries K L are connected in series. Spring jack 0 is preferably a multiple jack, that is, one of a plurality of jacks at which connection is preferably made with a called subscribers line.- The busy-test is also made at these jacks. Spring jack P is preferably the answering jack, that is, the jack at which connection is preferably made with a calling subscribers line. This latter jack is provided with a ring 70 which is dead. This dead ring 70 is for the purpose of preventing the tip contact a, of answering plug R from making con tact with jack contact 7' of jack P when connection is being made between plug R and jack P. If tip contact a, makes connection with jack contact 7', it closes the circuit of batteries K and L through impedance coil F, tip strand v.0 tip contact a jack contact 7', winding 6 of relay N, armature spring r, contact 9, conductor 8, and lamp t, thereby operating relay N. Relay N should not be operated in this manner, hence we provide the dead ring it, of jack P, for the purpose of preventing this operation of the relay N during the process of making connection with spring jack P. As calling plug S is preferably connected with a multiple jack of a telephone line, and as the operators listening key D is preferably depressed when such connection is being made, thus disconnecting tip contact of plug S from pole or, of battery K, as will be hereinafter described, the multiple jacks do not require this dead ring k for the purpose of preventing contact between tip contact i, of plug S, and jack contact Therefore the multiple jacks are preferably constructed as shown at O. In jack O, the contactj is preferably used for the busy-test terminal.

The line or subscriber B, shown upon the right of the drawing, is similar to the line of subscriber A, except that conductor Z of line B is connected through contact 7),, spring 10, and conductor :v, to pole 3 of battery M. Like characters indicate like parts in linesA and B. lVhen armature a, of relay N belonging to line B, is attracted, it disengages springs a, w and r, from contacts 0, p and g, respectively.

In the plug-cord circuit, the tip contact a, of answering plug R, is connected through tip strand e0 condenser '0 conductor 1 contact 0,, spring 6 contact m spring Z and tip strand 6,, to tip contact i of calling plug S. Sleeve contact 0 of answering plug R, is connected through sleeve strand m condenser conductor 8,, spring i contact 71 contact as, spring 0 and sleeve strand M to sleeve contact of calling plug S. The third contact 6,, of answering plug R, is connected through strand (Z and signal lamp 0 to pole n, of battery K. The third contact ,4, of calling plug S, is connected through strand Z and signal lamp 7L3, to pole .2 of battery M. Tip strand 10 is connected through impedance coil F, to pole m of battery K. Conductor r, is connected through impedance coil G, to pole m of battery K. Sleeve strand as is connected through impedance coil H, to pole n of bat tery K. Conductor s, is connected through impedance coil 1, to pole n, of battery K.

When the listening key D is depressed, springs 6 and thereof are disengaged from contacts 0 and 712, respectively, and engaged with contacts (6 and j respectively. Spring 0 also engages contact 0 when listening key D is depressed. The insulating pin (Z, is interposed between springs b, and 6 for the purpose of causing spring 6 to operate with spring 72 The operators telephone, not shown in the drawing, is connected from spring 6 to contact Contact a, is adapted to be connected with a busy-test arrangement. It will be noticed that when the listening key D is depressed. tip contact 2', is disconnected from pole m, of battery K,

at contact 0 and is connected in circuit with contact (6 Thus, if tip contact of calling plug S, touches jack contact 7' of jack 0 belonging to line B, while the listening key D is depressed, it does not close the circuit of battery K through relay N and thereby operate relay N as above stated.

Then the ringing key E is depressed, springs Z and 0 thereof are disengaged from contacts m and n respectively, and engaged with contacts is, and respectively. Contacts 70 and Q: are adapted to be connected with a calling source of electricity. Tf subscriber A desires to talk with subscriber 13, he lifts his telephone receiver from the switch-hook, in the usual manner, thereby closing the circuit between the limbs of his telephone line, in a manner well understood, and causing current from batteries K and L, to flow through conductor m, contact 0, spring n, limb b of the telephone line, substation A, limb 0, spring r, contact 9, conductor s, and line lamp t, thus lighting the latter which conveys to the operator the signal for connection. The operator thereupon, lifts answering plug it and inserts same into answering jack P of line A. The insertion of plug R into jack P, closes the circuit of battery K through impedance coil F, tip

strand 10 tip contact (1,, jack contact 72., winding (Z of relay N, limb Z) of the telephone line, substation A, limb 0, winding 6 of relay N, jack contact 7', sleeve contact 0 sleeve strand m and impedance coil H. It will be seen that winding d and impedance coil F are now shunted by conductor m, but as battery L is preferably small as compared with battery K, and as the resistance of lamp 2? is preferably high, there will be sulii cient current flowing from battery K through winding 6 of relay LT to cause arm ature 2 of the said relay to operate and thereby disengage spring n from contacts 0 and p, and spring 1 from contact q. When the armature .2 is thus actuated, the shunt m is taken from winding (Z and impedance coil F, and the circuit through battery L and lamp 2? is broken from the relay, and therefore the entire current which flows from battery K over the line A, now traverses both windings (Z and e of relay N and thereby holds the armature e in an attracted position, due to the magnetic pull produced by both windings of the relay. The circuit through lamp 2? is now broken at contact 9, and lamp 2? is therefore extinguished. The operator then depresses her listening key D and thereby connects her telephone set with the talking strands of the plug-cord circuit, in a manner well understood. Upon learning that subscriber B is the subscriber called for, the operator tests the line of subscriber B to ascertain whether it is in use or not. (The method of making the busy-test is not described here.)

Assuming that the line of subscriber B is not in use, the operator inserts the calling plug S into a spring jack Q of line B. The insertion of plug S into jack t), closes the circuit of battery M through supervisory lamp h strand Z contact j jack contact conductor Z, contact 17 spring to, and conductor 0:, thereby lighting lamp 7L3 which shows to the operator that subscriber B has his receiver on the switchhook. The insertion of plug S into a jack of line B, may also close the circuit of battery L through impedance coil I, conductor 8,, spring 2',, contact k contact 71,, spring 0 sleeve strand a sleeve contact jack contact j, winding 6 of relay N, spring a", contact 9, conductor 8, and signaling device 25, if the listening key D is then in normal position, but as the voltage of battery L is preferably low, and as the resistance of signaling device t is preferably high, there will not be sufficient current flowing over this circuit to operate the armature 2 of relay N nor to cause signaling device 1; to display a signal. The operator then depresses the ringing key E, thereby signaling subscriber B in a manner well understood. When the operator depresses the ringing key E, she may thereby restore the listening key D to its normal position. When subscriber B responds to the call and lifts his telephone receiver from the switch-hook, he closes the circuit of battery K through impedance coil G, conductor 1 contact 0,, spring 6 contact m spring Z tip strand (6,, tip contact '5 jack spring 7L belonging to line'B, winding (Z of relay l limb Z) of the telephone line, substation B, limb c, winding 6 of relay N, jack contact j, sleeve contact k sleeve strand u spring 0 contact an, contact k spring 6,, conductor 8 and impedance coil I, thereby actuating armature 2,, of relay N and disengaging springs 11., w and r, from cont-acts 0, p and g, respectively. This actuation of armature 2 breaks the circuit of battery M through supervisory lamp 72. at contact 22,, and thereby extinguishes lamp 7L3. Subscribers A and B are now connected for conversation with each other, and all signals are inactive.

When the conversation is completed and subscriber A hangs his telephone receiver upon the switch-hook, he breaks the circuit between the limbs of his telephone line, at his substation, in a manner well understood, and thereby stops the flow of current from battery K through his relay N. This releases armature a, of relay N and thereby causes spring a to engage contacts 0 and p, and spring r to engage contact 9. Spring an engaging contacts 0 and p, closes the circuit of battery K through conductor we, contact 0, spring 7, contact p, conductor Z, jack spring 2', contact 6 strand (Z and'supervisory lamp 6,, and thereby lights the latter which conveys to the operator the signal for disconnection. When subscriber B hangs his telephone receiver upon the switch-hook, he causes armature z, of relay N belonging to his line, to release, in a manner similar to that just described for subscriber A. When armature 2 releases, it causes springs n, 'w, and 1", to engage contacts 0, p and 9, respectively. Spring 20 now closes the circuit of battery M through supervisory lamp 7Z3, strand 1,, contact 1' jack spring 2', conductor Z, contact 79 spring w, and conductor :12, thereby lighting lamp 72, which conveys to the operator the signal for disconnection. When the operator receives both disconnect signals, from subscribers A and B, respectively, she withdraws the connecting plugs R and S from their respective spring jacks, and thereby extinguishes lamps c and 71 and restores all circuits and apparatus to their normal condition.

The drawings preferably illustrate two forms of line circuits and two forms of supervisory signal circuits. If it is desired to use each of the plugs of the system with all of the lines of the system, in the operation of the latter, the line circuits should all be similar to line A and the supervisory signal circuits should all be similar to the circuit of signal 6 or else the line circuits should all be similar to line B and the supervisory signal circuits should all be similar to the circuit of signal k to work properly together.

WVhile we have shown lamps for the line signaling devices and supervisory signaling devices, we desire it to be understood that other suitable forms of electrically-operable signaling devices may be used for one or more of the signals.

lVhile we have illustrated our invention in connection with particular types of apparatus, such as spring jacks, connecting plugs, connecting cords, keys, signaling devices, impedance coils, relays, and sources of electricity, we do not wish to confine ourselves to such particular apparatus. We also desire it to be understood that any suitable generator may be substituted for battery M, with goods results.

We do not wish to be limited to the particular forms of the invention herein set forth, as various modifications thereof may be made without departing from the scope of the appended claims.

Having thus described our invention, what we claim as new and desired to secure by Letters Patent, is-

1. The combination with a telephone line, of a relay in the talking circuit thereof, exterior of the subscribers signaling-in circuit, a connection terminal for the line, a conductor adapted to be connected with the connection terminal, a signaling device and a source of electricity in circuit with the said conductor, and means operated by the said relay for opening and closing the circuit of the said source through the said signaling device, when connection is made with the line.

2. The combination with a telephone line, of a relay in the talking circuit thereof, exterior of the subscribers signaling-in circuit, a source of electricity associated with the relay, aconnection terminal for the line, a conductor adapted to be connected with the connection terminal, a signaling device associated with the said conductor and with the said source, and means operated by the said relay for opening and closing the circuit of the said source through the said signaling device, when connection is made with the said line terminal, and thereby controlling the operation of the said signaling device, substantially as described.

3. The combination with a telephone line terminating in suitable connection terminals, of a relay included in the talking circuit of the line, a plug-cord circuit adapted to be connected with the line, a signaling device associated with a strand of the con necting cord, a source of electricity associated with the said relay, the plug-cord circuit and the signaling device, means for closing the circuit of the said source through the signaling device when connection is made with the telephone line, and means whereby connection with the telephone line when in use closes the circuit of the said source through the said relay and thereby actuates the said relay and opens the circuit through the signaling device, substantially as described.

4-. The combination with a telephone line and suitable connection terminals therefor, of a relay included in the talking circuit of the line, a plug-cord circuit adapted to be connected with the line, a source of electricity associated with the plug-cord circuit, a signaling device, a second source oi electricity connected through the signaling device to a st "and of the connecting cord, means tor closing the circuit of the said second source through the signalin device when connection is made with the telephone line, and means for closing the circuit of the first mentioned source through the said relay when connection is made with the line when in use, thereby actuating the said relay and opening the circuit through the said signaling device substantially as described.

5. The combination with a telephone line and connection terminals therefor, of a relay included in the talking telephone line, a plug-cord circuit adapted to be conductively connected with the telephone line, a supervisory signaling device connected in circuit with a strand of the connecting cord, a source of electricity associated with the plug-cord circuit and with the said signaling device, means for closing the circuit of the said source through the said signaling device when connection is made with the line, and means for alternately closing and opening the circuit of the said source through the said relay, only when connection is made with the line, thereby causing the said reay to alternately open and close the circuit of the said source through the said signaling device, substantially as described.

6. The combination with a telephone line and connection terminals therefor, of a relay included in the talking telephone line, a plug-cord circuit adapted to be conductively connected with the telephone line, a supervisory signaling device connected in circuit with a strand of the connecting cord, a source of electricity associated with the plug-cord circuit, a second source of electricity associated with the said signaling device, means for closing the circuit of the said second source through the said signaling device when connection is made with the line, and means for alternately closing and opening the circuit of the first mentioned source through the said relay, when connection is made with the line, thereby causing the said relay to alternately open and close the circuit of the said second source through the said signaling device, substantially as described.

7. In combination, a talking telephone line, a relay included therein exterior of the subscribers signaling-in circuit, a connection terminal for the line, a connecting plug and cord adapted to be connected with the connection terminal. of the line, a signaling device connected in circuit with a strand of the connecting cord, a source of electricity associated with the connecting cord, and means whereby the relay controls the circuit of the signaling device, when connection is made with the line, and thereby controls the operation of the signaling device, substantially as described.

8, In combination, a metallic talking telephone line, a relay included therein, a connection terminal provided with contacts for the respective limbs of the metallic line, a third contactof the connection terminal, a metallic connecting cord adapted to be connected with the metallic line, a third strand of the connecting cord adapted to be connected with the said third contact of the said connection terminal, a signaling device connected in circuit with the said third strand of the connecting cord, a source of electricity associated with the connecting cord, and means whereby the said relay opens and closes the circuit of the said. signaling device, when connection is made with the line, and thereby controls the operation of the signal ing device, substantially as described.

9. The combination with a telephone line, of connection sockets for the line, a guide ring at each socket for guiding the connecting plug, conductors connecting all of the said guide rings but one, together and to a limb of the telephone line, and a contact member at the remaining socket connected to the said limb of the line, the said one guide ring being normally insulated from all other conductive portions, for purposes substantially as described.

10. The combination with an electrical transmitting line, of a number of connection terminals connected with the line, an electrically-operable device in the said line between the several connection terminals and asubstation, a conductor adapted to be connected with any of the connection terminals, a signaling device and a source of electricity in circuit with the said conductor, and means operated by the said electrically-operable device for opening and closing the circuit of the signaling device when connection is made with the line.

11. The combination with a telephone line, of spring jacks connected in multiple to the said line, one said jack being provided with an insulated guide-ring or sleeve, a relay included in the talking circuit only, of

the line, a plug-cord circuit adapted to be connected with any of the said spring jacks of the line, a signaling device connected to a strand of the connecting cord, a source of electricity associated with the plug-cord circuit and with the signaling device, and means whereby the said relay controls the operation of the said signaling device when connection is made with the telephone line, substantially as described.

12. The combination with an electrical transmitting line extending from a substation to suitable connection terminals, of an electrically-operable device in the said line between the several connection terminals and the substation, a supervisory signaling device adapted to be placed under control of the said electrically-operable device when connection is made with the line, and means whereby the said electrically-operable device is adapted to open and close the circuit of the said signaling device to operate same.

13. The combination with a telephone line, of spring jacks connected in multiple to the line, a guide-ring for each jack and all but one being connected together and to a limb of theline, the remaining guide-ring being insulated from all other conducting portions, a relay in the talking circuit of the line, and a signal circuit adapted to be connected with a terminal of a jack when connection is made with the line, the said relay then controlling the operation of the signal.

14. The combination with a telephone line, of spring jacks connected in multiple to the line, one said jack being provided with an insulated sleeve, a relay included in the talking circuit of the line between all of the said spring jacks and the exterior line, a connecting plug adapted to be conductively connected with any of the'several spring jacks of the line, a connecting cord connected to the connecting plug, a signaling device connected to a strand of the connecting cord, a source of electricity associated with the connecting cord, a second source of electricity associated with the said signaling device, and means whereby the said relay controls the operation of the said signaling device when connection is madewith the telephone line, substantially as described.

15. A telephone line for signaling a central station, a branch therefrom including a relay, connecting means for the line, and a signaling device associated with the connecting means, the said relay directly controlling the operation of the signaling device when connection is made with the line.

16. A telephone line for signaling a cen tral station, a branch therefrom including an electrically-operable device, and a signal- ,ing device arranged to be connected with the line when connection is made therewith for conversation, the said electricallyoperable device then controlling the operation of the said signaling device.

17. A telephone line for signaling a central station, a branch therefrom to a connection terminal and including a relay, said relay being entirely included in said branch, connecting means for the line, a signaling device associated with the connecting means, and means whereby the said relay directly controls the operation of the signaling device when connection is made with the line.

18. The combination with a telephone line, of a branch therefrom extending to a connection terminal and including an electrically-operable device, the said device being entirely included in said branch, connecting means for the said branch, a supervisory signaling device adapted to be associated wit-h the said electrically-operable device, and means whereby the said electrically-operable device directly controls the operation of the said signaling device when connection is made with the line.

19. The combination with a telephone line for signaling a central station, of a branch therefrom including a relay and extending to a number of connection terminals, connecting means for the line, a signaling device associated with the connecting means, and means whereby the said relay directly controls the operation of the signaling de vice when connection is made with the line.

20. The combination with a telephone line, of a branch of the line extending to a connection terminal, a relay entirely included in the said branch, signaling devices arranged to be controlled by the relay, and means for causing the relay to directly control the operation of the signaling devices, one as a line signal and one as a supervisory signal.

21. The combination with a telephone line and a relay in the talking circuit thereof, of connecting means for the line, a source of electricity associated with the said relay and connecting means, a signaling device in circuit with a second source of electricity and associated with the said connecting means, the said signaling circuit being entirely separate from the telephone line circuit, and means whereby the said. relay opens and closes the circuit of the said signaling device when connection is made with the line, thereby controlling the operation of the signal.

22. The combination with a telephone line provided with suitable connecting means, of an electrically-operable device in the talking circuit of the line; a source of electricity associated with the line; and a signal circuit including a signaling device, a second source of electricity, a conductor of a connecting circuit for the line and a contact of the said connecting means; the said signal circuit being entirely separate from the telephone line circuit; the said electrically-operable device being arranged to open and close the said signal circuit when connection is made with the line, to operate the signal.

23. The combination with a telephone line and connecting sockets therefor, of a relay in the talking circuit of the line; a source of electricity associated with the line; and a local circuit including a signaling device, a second source of electricity, a terminal of a connecting plug and a contact of a connecting socket; the said local circuit being entirely separate from the telephone line circuit; the said relay being arranged to open and close the circuit of the signaling device when connection is made with the line, to control the operation of the said signaling device.

24. A telephone line for signaling a central station, a branch therefrom including a relay, said relay being entirely in said branch, a source of electricity associated with the line, connecting means for the line, and a signaling device in series with a second. source of electricity and associated with the connecting means, the said relay directly controlling the operation of the signaling device when connection is made with the line.

25. A telephone line for signaling to a switchboard, a branch therefrom entirely including an electrically-operable device, a source of electricity associated with the said device, a supervisory signaling device in circuit with a second source of electricity and adapted to be placed under direct control of the said electrically-operable device, and means for operating the latter.

26. A telephone line normally extending from a substation to a central station, a branch therefrom to a connection terminal, the said branch entirely including a relay, a source of electricity associated with the line, asupervisory signaling device in circuit with a second source of electricity and adapted to be placed under direct control of the said relay when connection is made with the line, and means for causing the said relay to operate the said signaling device.

27. A telephone line for signaling a central station, a branch therefrom including a relay and terminating in a number of connection terminals, a source of electricity asso ciated with the line, connecting means for the line adapted to be connected with any of the several connection terminals, a signaling device in circuit with a second source of electricity and associated with the connecting means, and means whereby the said relay clirectly controls the operation of the signaling device when connection is made with the line.

28. The combination with a telephone line normally extending to a central station, of a branch therefrom entirely including a relay, a source of electricity associated with the relay, connecting means to be connected with said branch, a signaling device in circuit with a second source of electricity and associated with the said connecting means, and means whereby the relay directly controls the operation of the said signaling device when connection is made with the line.

29. The combination with a telephone line, of a branch therefrom extending to a con nc-ction terminal and entirely including an electrically operable device, connecting means for the line, a source of electricity associated with the line, a supervisory signaling device in circuit with a second source of electricity and adapted to be associated with the said electrically-operable device, and means whereby the said electrically-operable device directly controls the operation of the said signaling device when connection is made with the line.

30. The combination with a telephone line normally including signaling apparatus at the central station, of a normally open branch therefrom including a relay and extending to connection terminals in multiple, connecting means to be connected with the line, a source of electricity associated with the line, a second source of electrictiy in series with a signaling device associated with the said connecting means, and means whereby the said relay directly controls the operation of the said signaling device when connection is made with the line.

31. The combination with a telephone line, of a normally open branch of the line, a relay wholly included in the said branch, a signaling device in circuit with a source of electricity and associated with the line, a second signaling device in circuit with a second source of electricity and associated with a plug-cord circuit, the said second signaling device being adapted to be placed under direct control of the relay, and means for 1,0e5gece causing the relay to operate the said signaling devices, one as a line signal and one as a supervisory signal.

In combination, a metallic talking telephone line, a relay included therein, a connection terminal provided with contacts for the respective limbs of the metallic line, a third contact oi? the connection terminal, a metallic connecting cord adapted to be connected with the metallic line, a third strand of the connecting cord adapted to be connected with the-said third contact of the said connection terminal, a signaling device in circuit with a source of electricity and the said third strand of the connecting cord, a second source of electricity associated with the connecting cord, and means whereby the said relay opens and closes the circuit of the said signaling device when connection is made with the line, to control the operation of the signaling-device, substantially as described.

33. In combination, a metallic talking telephone line, a relay included therein, connection terminals each provided with contacts for the respective limbs of the metallic line, a third contact for each of the connection terminals, a. metallic connecting cord adapted to be connected with the metallic line, a third strand of the connecting cord adapted to be connected with any of the said third contacts of the connection terminals, a signaling device connected in circuit with the said third strand of the connecting cord, a source of electricity associated with the connecting cord, and means whereby the said relay opens and closes the circuit of the said signaling device when connection is made with the line to control the operation of the signaling device, substantially as described.

3-5:. In combination, a metallic talking telephone line, a relay included therein, connec tion terminals each provided with contacts for the respective limbs of the metallic line, a third contact for each of the connection terminals, a metallic connecting cord adapt ed to be connected witlrthe metallic line at any of the connection terminals, a third strand of the connecting cord adapted to be connected with any of the said third contacts of the connection terminals, a signaling device in circuit wth a source of electricity and the said third strand of the connecting cord, a second source of electricity associated with the connecting cord, and means where by the said relay opens and closes the circuit of the said signaling device when connection is made with the line, to control the operation of the signaling device, substantially as described.

35. The combination with a calling telephone line, or" a normally open branch there from entirely including relay and terminating in suitable connection terminals, a supervisory signaling device adapted to be I operated by the said relay, and an insulated a connection terminal and entirely including a relay, a plug-cord circuit adapted to be connected with the connection terminal, a signaling device connected to a strand of the connecting cord, a source of electricity associated with the plug-cord circuit and with the line, and a switch at the substation adapted to control the ope-ration of the said relay when connection is made with the line, the said relay thereby controlling the operation of the said signaling device, substantially as described.

37. The combination with a telephone line extending from a substation to a central station line signaling-device, of a branch therefrom extending to a connection terminal and including a complete winding of a relay, a plug-cord connecting circuit adapted to be connected with the connection terminal, a supervisory signaling device in circuit with a source of electricity and a strand of the connecting cord, a second source of electricity associated with the plugcord circuit and with the line, and a switch at the substation'adapted to control the operation of the said relay when connection is made with the line, the said relay thereby controlling the operation of the supervisory signaling device, substantially as described.

38. The combination with a telephone line and suitable connection terminals therefor, of an electrically-operable 'device included in the talking circuit of the line, a connecting circuit adapted to be connected with the line, a source of electricity associated with the connecting circuit, a signaling device, a second source of electricity connected in circuit with the said signaling device and a strand of the connecting circuit, means for operating the said signaling device from the said second source over its said circuit when connection is made with the line, and means for operating the said electrically-operable device only when connection is made with the line, and thereby causing same to control the operation of the said signaling device.

39. An electrically-operable device included in a telephone line between a number of connection terminals and a substation, a supervisory signaling device adapted to be associated with the said electrically-operable device when connection is made with the line, and means for causing the said electrically-operable device to open and close the circuit of the said signaling device when such connection is made.

40. An electrically-operable device included in a talking telephone line between a number of connection terminals connected in multiple and a substation, a signaling device adapted to be associated with the said electrically-operable device only when connection is made with the line, and means for causing the said electrically-operable device to open and close the circuit of the said signaling device when connection is made with the line.

41. The combination with a telephone line and a relay in the talking circuit thereof, of connecting means for the line, a source of electricity associated with the said relay and connecting means, and a signaling device in circuit with a second source of electricity and associated with the said connecting means, the said signaling circuit being entirely separate from the telephone line circuit, the said relay being adapted and arranged to open and close the circuit of the said signaling device to control the operation of the latter. when connection is made with the line.

42. The combination with a telephone line, of connection sockets for the line, a guide ring at several of the sockets. some of the said guide rings being conductively connected together and to a limb of the line, and one guide ring being normally insulated. from all of the other conductive portions, for purposes substantially as described.

43. In an electrical transmitting system, an electrically-operable device associated with a line thereof, said device serving to open the circuit of a signaling device associated with connecting means for the line at the time connection is made with the line.

44. An electrical transmitting line, an electrically-operable device associated there with, connecting means for the line, and a signaling device associated with the connccting means, the said electricallyoperable device being operated at the time connection is made with the line, to open the circuit of the signaling device whereby the latter is prevented from displaying a signal.

45. An electrical transmitting line, an electrically-operable device associated there with, connecting means for the line, and a signaling device associated with the connecting means, the said electrically-operable device being arranged to directly control the operation of the signaling device and to be operated only while connection is made with the line.

46. In a telephone system, a combined line circuit and connecting circuit having a relay, associated with the line and a signaling device associated with the connecting circuit, the said relay being operated over the combined line and connecting circuit to operate the signal.

d7. A telephone line for signaling a central station, a branch therefrom to a connection terminal including a relay, and a supervisory signaling device arranged to be under direct control of the relay while connection. is made with the line.

48. An electrical transmitting line for signaling a central station, a branch therefrom extending to a connection terminal and including an electrically-operable device, and a supervisory signal-initiating device ar ranged to be under sole control of the said electrically-operable device while connection is made with the line.

49. An electrical transmitting line for signaling a central station, a branch therefrom extending to a connection terminal and including an electrically-operable device, connecting means for the line, and a signalinitiating device associated with the said connecting means and under sole control of the said electrically-operable device while connection is made with the line.

50. An electrical transmitting line for signaling to a central station, a branch therefrom extending to a connection terminal and including an electrically-operable device, a signal-initiating device associated with the line and under control of the said electrically-operable device, connecting means for the line, a signal-initiating device associated with the said connecting means, and means whereby the latter said signal-initiating device is placed under sole control of the said electrically-operable device when connection is made with the line.

51. A telephone line for signaling to a central station, a branch therefrom extending to a connection terminal and including a relay, a line signal associated with the line and under control of the said relay, connecting means for the line, a supervisory signal associated with the said connecting means, and suitable circuit connections whereby the said supervisory signal is placed under direct control of the said relay when connection is made with the line.

An electrical transmitting line for sig naling a central station, an electrically-operable device associated with the line exterior of the said signaling line, and a supervisory signal-initiating device arranged to be under sole control of the said electrically-operable device while connection is made with the line.

An electrical transmitting line for signaling a central station, an electrically-operable device associated with the line exterior of the said signaling line, connecting means for the line, and an electroresponsive device associated with the said connecting means and adapted to be placed under control of the said electrically-operable device while connection is made with the line.

5 1. An electrical. transmitting line for signaling to a central station, an electricallyoperable device associated with the line exterior of the said signaling line, an electroresponsive device associated with the line and under control of the said electricallyoperable device, connecting means for the line, an electroresponsive device associated with the said connecting means, and means whereby the latter said electroresponsive device is placed under sole control of the said electrically-operable device when connection is made with the line.

55. A telephone line for signaling a central station, a relay associated with the line exterior of the said signaling line, a line signal associated with the line, connecting means for the line, a supervisory signal associated with the said connecting means, and suitable circuit connections whereby the said supervisory signal is placed under directcontrol of the said relay when connection is made with the line.

56. An electrical transmitting line, an electrically-operable device associated with the line, connecting means for the line, a signalinitiating device associated with the connecting means, and means whereby the said electrically-operable device is operated at the time connection is made with the line, to render the said signal-initiating device incapable of causing the display of a signal.

57. An electrical transmitting line, an electrically-operable device associated with the line, a supervisory signal adapted to be placed under control of the said electricallyoperable device when connection is made with the line, and means whereby the said electrically-operable device is operated at the time connection is made with the line, to render the supervisory signal inactive.

58. An electrical transmitting line, an electrically-operable device associated with the line, and a signaling device adapted to be placed under direct control of the said electrically-operable device when connection is made with the line, the said electrically-operable device being arranged to be operated only while connection is made with the line.

59. In an electrical transmitting system, a line circuit having an electrically-operable device associated therewith. and a connecting circuit having a signaling device associated therewith, the said electrically-operable device being operated over combined portions of the line and connecting circuits to open and close the circuit of the said signaling device.

60. A telephone line having a plurality of connection sockets for the'line, a guide ring at some of the sockets, some of the said guide rings being conductively connected together and to a limb of the line, and one of the said guide rings being normally insulated from the other guide rings and from the limbs of the line.

61. The combination with a metallic telephone line, of a relay included in both limbs of the line, a connecting circuit for the line, and a supervisory signaling device associated with the connecting circuit and under direct control of the relay when connection is made with the line.

62. The combination with a metallic telephone line, of relay mechanism included in both talking limbs of the line, a connecting circuit for the line, and a supervisory signaling device associated with the connecting circuit and under direct control of the said relay mechanism when connection is made with the line.

63. The combination with a metallic electrical transmitting line, of an electroresponsive device included in both limbs of the line, connecting means for the line, and a signalinitiating device associated with the said connecting means and under sole control of the said electroresponsive device when connection is made with the line.

64. The combination with a metalliceleo trical transmitting line, of electroresponsive mechanism included in bot-h main transmission limbs of the line, connecting means for the line, and a signal-initiating device associated with the said connecting means and under sole control of the said electroresponsive mechanism when connection is made with theline. l

65. A telephoneline having a plurality of connection sockets with guide rings therefor, one or more of the said guide rings being connected to a source of electricity, and one of the said guide rings being normally insulated from the others, for purposes substantially as set forth.

66. In an electrical transmitting system, a line circuit having an electroresponsive device associated therewith, and a connecting circuit having a signal-initiating device associated therewith, the said electroresponsive device being operated over combined portions of the line and connecting circuits whereby it exercises sole control over the said signal-initiating device.

67 Anelectrical transmitting line, an electroresponsive device associated with the line, and a signal-initiating device adapted to be placed under sole control of the said electroresponsive device when connection is made with the line, the said electroresponsive device being arranged to be operated only while connection is made with the line.

68. An electrical transmitting line, an electroresponsive device associated therewith, connecting means for the line, and a signalinitiating device associated with the connecting means, the said electroresponsive. device being operated at the time connection is made with the line, to control the operation of the said signal-initiating device.

69. A telephone line having a low-resistance relay in the path of talking currents, and a supervisory signal under direct control of the relay when connection is made with the line.

70. The combination with a telephone line, of a branch therefrom to a connection terminal, a relay in said branch, and a supervisory signal adapted to be placed under direct control of the relay when connection is made with the line, the said relay having a back contact controlling the operation of the supervisory signal.

71. lhe combination with a telephone line, of a branch therefrom to a connection terminal, a relay in said branch, and a supervisory signal adapted to be placed under direct control of the relay when connection is made with the line.

72. The combination with a metallic elec' trical transmitting line extending conductively to a connection terminal and having one or more branch connections from the main transmission limb or limbs of the line, of electroresponsive mechanism having energizing means therefor included in both main transmission limbs of the line whereby current in either one or both of the main limbs of the line causes the operation of at least a portion of the said electroresponsive mechanism, the latter controlling the said branch connections from the line, with respect to the main line, a connecting circuit for the line, and a supervisory signal-initiating device associated with the said connecting circuit and adapted to be placed under sole control of the said electroresponsive mecha nism when connection is made with the line.

73. The combination with a metallic telephone line extending conductively to a connection terminal and having one or more branch connections from the talking limb or limbs of the line, of relay mechanism having energizing means therefor included in both talking limbs of the line whereby current in either oneorboth of the talking limbs of the line causes the operation of at least a portion of the said relay mechanism, the latter controlling the said branch connec tions from the line, with respect to the main line, a connecting circuit for the line, and a supervisory signaling device associated with the said connecting circuit and adapted to be placed under direct control of the said relay mechanism when connection is made with the line.

74. The combination with a metallic electrical transmitting line extending conductively to a connection terminal, of electroresponsive mechanism having energizing means therefor included in both main transmission limbs of the line whereby current in either one or both of the main limbs of the line causes the operation of at least a portion of the said electroresponsive mechanism, a connecting circuit for the line, and a supervisory signal-initiating device associated with the said connecting circuit and adapted to be placed under sole control of the said electroresponsive mechanism when connection is made with the line.

75. The combination with a metallic telephone line extending conductively to a connection terminal, of relay mechanism having energizing means therefor included in both talking limbs of the line whereby current in either one or both of the talking limbs of the line causes the operation of at leasta portion of the said relay mechanism, a connecting circuit for the line, and a supervisory signaling device associated with the said connecting circuit and adapted to be placed under direct control of the said relay mechanism when connection is made with the line.

7 6. The combination with a telephone line, of electroresponsive mechanism having low-resistance energizing means therefor in the path of talking current-s, a connecting circuit for the line, and a supervisory signaling device associated with the said connecting circuit and adapted to be placed under direct control of the said electroresponsive mechanism when connection is made with the line.

77. The combination with a metallic telephone line, of electroresponsive mechanism having low-resistance energizing means therefor in both limbs of the line in the path of talking currents, a connecting circuit for the line, and a supervisory signaling device associated with the said connecting circuit and adapted to be placed under direct control of the said electroresponsive mechanism when connection is made with the line.

78. The combination with an electrical transmitting line extending conductively to a connection terminal, and a connecting circuit therefor, of supervisory signaling mechanism associated with the said connecting circuit, and electroresponsive mechanism having energizing means therefor included in a main transmission limb of the line, the said electroresponsive mechanism being adapted to exercise sole control over the said signaling mechanism when connection is made with the line.

79. The combination with a telephone line extending conductively to a connection terminal, and a connecting circuit therefor, of supervisory signaling mechanism associated with the said connecting circuit, and relay mechanism having energizing means therefor included in a talking limb of the line, the said relay mechanism being adapted to exercise sole control over the said signaling mechanism when connection is made With the line.

80. A telephone line circuit for signaling a central station, a relay associated with the line, a normally-open branch circuit from the said line circuit containing a Winding of the said relay, a supervisory signal adapted to be placed under direct control of the said relay when connection is made with the line, and means for closing the said normallyopen branch circuit when connectiOn is made with the line.

81. A telephone line circuit for signaling a central station, a. relay associated with the line, a normally-open branch circuit from the said line circuit containing a winding of the said relay, a connecting circuit for the line, a supervisory signal-lnitiating device associated with the said connecting circuit and adapted to be placed under sole control of the said relay when connection is made with the line, and means for closing the said normally-open branch circuit through a connection terminal when connection is made with the line, to affect the condition of the said relay.

82. The combination with a metallic electrical transmitting line extending conductively to a connection terminal, of electroresponsive mechanism having energizing means therefor in both main transmission limbs of the line, a connecting circuit for the line, and a supervisory signal-initiating device associated with the said connecting circuit and adapted to be placed under sole control of at least a portion of the said electroresponsive mechanism when connection is made with the line.

83. The combination with a metallic telephone line extending conductively to a connection terminal of relay mechanism having energizing means therefor included in both talking limbs of the line, a connecting circuit for the line, and a supervisory signal-initiating device associated with the said connecting circuit and adapted to be placed under sole control of at least a portion of the said relay mechanism when connection is made with the line.

84:. The combination with a metallic telephone line of a relay having energizing means therefor included in both limbs of the line, a connecting circuit for the line and a supervisory signal-initiating device associated with the connecting circuit and adapted to be placed under sole control of the said relay when connection is made with the line, the said relay having a contact adapted to be closed upon the denergization of the relay to control the said device.

85. A telephone line having a limb extending conductively to a connection terminal, an electroresponsive device having energizing means therefor included in the said limb, a connecting circuit for the line, and a supervisory signal-initiating device associated with the connecting circuit and adapted to be placed under sole control of the said electroresponsive device when connection is made with the line.

86. The combination with a metallic telephone line, of relay mechanism having energizing means therefor included in both limbs of the line, a connecting circuit for the line, and a supervisory signal-initiating device associated with the connecting circuit and under sole control of the said relay mechanism when connection is made with the line.

87. The combination with a metallic telephone line, of a relay having energizing means therefor included in both limbs of the line, a connecting circuit for the line, and a supervisory signaling device associated with the connecting circuit and adapted to be placed under direct control of the said relay when connection is made with the line, the said relay having a contact adapted to be closed upon the denergization of the relay to control the said signaling device.

As inventors of the foregoing we hereunto subscribe our names in the presence of two subscribing witnesses, this 26th day of November, A. D. 1904;.

FREDERICK R. PARKER. ELMER It. CORWIN. Witnesses:

A. MILLER BELFIELD, I. C. LEE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, I). G. 

